Question

In the first experiment, a sample of Ascorbic acid produced in the laboratory contains 15.0g of carbon and 20.0g of oxygen. In the second experiment, Ascorbic acid is isolated from lemon containing 42.9% carbon. Show that the data is in accordance with the law of constant proportion.

Answer 1

Step 1: Definition of law of constant proportions

The chemical compounds contain elements in a fixed ratio by mass. This implies that any pure sample of a compound, no matter the source, will always consist of the same elements that are present in the same ratio by mass.

Step 2: Identify the given data

Mass of Ascorbic acid: 35g

Mass of carbon in given sample: 15g

Mass of carbon in another sample: 42.9%

Step 3: Applying the law of constant proportions

Percentage of carbon in given sample is: $\frac{(\mathrm{Mass}\mathrm{of}\mathrm{carbon}\mathrm{in}\mathrm{given}\mathrm{sample})}{(\mathrm{Total}\mathrm{mass}\mathrm{of}\mathrm{the}\mathrm{sample})}x100$ = $\frac{15}{35}x100$ $=42.85\%$

The percentage of carbon in another sample is: $42.85\%$

1. From the above steps, we can conclude that the percentage of carbon in both the samples are same.
2. Hence, the results are in accordance with the law of constant proportion.